Fitokemijska karakterizacija macerata peteljki grožđa

undergraduate thesis

• Title (english): Phytochemical characterization of grape stems macerate
• Author: Monika Barač
• Mentor: Jasna Mrvčić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Fermentation and Yeast Technology); Zagreb
• Defense date and country: 2018-06-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Peteljke grožđa čine do 25% otpada koji nastane nakon proizvodnje vina. No, zbog polifenola koje sadrže, a koji imaju antioksidacijska i antikancerogena svojstva, peteljke se ne moraju nužno smatrati otpadom nego se mogu iskoristiti daljnom preradom. U svrhu proizvodnje biljnog likera maceracijom peteljki u etanolu, kao načina njihovog racionalnog iskorištenja, analizirani su uzorci maceracije peteljki grožđa u 45, 70 i 96%-tnom etanolu s omjerima peteljki i etanola 1:5 i 1:10. Određena je količina ukupnih polifenola spektrofotometrijski pomoću Folin-Ciocalteou reagensa, njihova antioksidacijska aktivnost FRAP i DPPH metodama te njihove kromatske karakteristike i pH vrijednosti. Najveći sadržaj polifenola imali su macerati dobiveni maceracijom peteljki nakon 2 mjeseca, s omjerom peteljki i etanola 1:5, a najviše se polifenola ekstrahiralo u 70%-tnom etanolu. Najveću antioksidacijsku aktivnost pokazali su uzorci nakon maceracije od jednog mjeseca s omjerom peteljki i etanola 1:5.

Abstract (english)

Grape stems make up to 25% of the waste generated after wine production. Because of the polyphenols they contain, which show antioxidant and anticancer properties, they do not necessarily have to be considered as a waste, but they can instead be utilized in further processing. With the purpose of their rational utilization by making a herbal liquor by macerating them in ethanol, the samples of maceration of grape stems in 45, 70 and 96% ethanol with stems and ethanol ratios of 1:5 and 1:10 have been analysed. Parameters which were determined were their amount of total polyphenols spectrophotometrically with Folin-Ciocalteu reagent, their antioxidant activity by FRAP and DPPH methods, their chromatic characteristics and pH values. The macerates with the highest content of polyphenols were the ones obtained after 2 months of maceration, with the ratio of stems and ethanol 1:5, and the macerate with the most polyphenols extracted was the one with 70% ethanol. The highest antioxidant activity was determined in the macerates obtained after 1 month of maceration with the ratio of stems and ethanol of 1:5.

• Keywords: grožđe; liker; maceracija; peteljke; polifenoli
• Keywords (english): grape; liquor; maceration; polyphenols; stems
• Language: croatian
• URN:NBN: urn:nbn:hr:159:934727
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2018-06-14 12:20:42